This application relates to a method and apparatus to treat an aneurism, and more particularly to a patch for treating an aneurism which is configured to form an adherence between the patch and an area of a vessel wall adjacent to an aneurism mouth and the adherence maintains a fixed position of the patch relative to the aneurism mouth.
There are several devices which exist that are used for the repair of aneurysms. U.S. Pat. No. 4,512,238 discloses a device for transluminal repair of, and restoring patency of, a weakened or damaged vessel uses a nitinol wire, previously memory-shaped into a straight wire and inserted into the vessel requiring repair. When placed in the body and stripped of heat insulation the wire warms and returns to a preselected coiled dimensions to support the vessel wall. One problem with this device is the difficult task of attaching a sleeve to the wire support because the wire is many times longer than the sleeve at the time it is inserted.
U.S. Pat. No. 4,140,126 discloses another device for repairing an aneurism. The device is mounted on the outside of a carrier catheter and is positioned in the vessel in a collapsed form, smaller in diameter that of the vessel. The device is then expanded onto the vessel well by the use of a separate mechanical expanding apparatus which is controlled by the user from outside the body.
U.S. Pat. No. 4,787,899 describes a system of positioning a graft within a body lumen. The graft is loaded into a guide which is inserted into the lumen. An inflatable balloon is used to anchor the distal end of the graft onto the wall of the lumen. The guide is then pushed upstream, pulling the folded graft out of the guide and onto the wall of the lumen where staples end anchor it into the wall of the lumen. One problem with this device is that the balloon providing the anchor for the distal end of the graft while the guide is moved upstream may not provide enough pressure on the wall of the vessel to prevent slippage which could result in misplacement of the graft.
It would be desirable to provide an aneurism patch which does not have a coil configuration and which adheres to the vessel wall adjacent to the mouth of the aneurism. It would be further desirable to provide an aneurism patch which has non-electrically activated deployed state configured to be positioned adjacent to the mouth of the aneurism. Yet it would still further desirable to provide an aneurism patch which has an electrically activated deployed state that is configured to be positioned adjacent to the mouth of the aneurism.
An object of the invention is to provide a method and apparatus for treating aneurysms.
Another object of the invention is to provide an aneurism patch which is positioned over a mouth of an aneurism.
Still another object of the invention is to provide an aneurism patch which has a non-electrically deployed state that is positioned over a mouth of an aneurism.
Yet another object of the invention is to provide an aneurism patch which is introduced into a vessel in a stowed state and is positioned over the mouth of the aneurism in a deployed state.
A further object of the invention is to provide an aneurism patch with a vessel interface side that includes a plurality of anchor elements.
Still another object of the invention is to provide an aneurism patch forms a mechanical adherence between the patch and the vessel wall adjacent to the aneurism mouth.
Yet another object of the invention is to provide an aneurism patch with an aperture configured to be coupled to a low pressure source.
Another object of the invention is to provide an aneurism patch at least partially made of a material with an internal stress and a pre-defined shape, where the internal stress moves the patch from a stowed state to the pre-defined state.
Still another object of the invention is provide an aneurism patch that is formed of a thermally active material that moves to a pre-defined shape when electrically heated.
A further object of the invention is to provide an aneurism patch which is made of a shape memory alloy (SMA) element with an activation threshold greater than body temperature.
These and other objects of the invention are achieved in an aneurism patch apparatus for treating an aneurism formed in a vessel includes a patch with a vessel interface side and an opposing non-interface side. The patch is formed of a sufficiently flexible material to provide a patch stowed state when the patch is delivered through the vessel and a patch deployed state when the patch is at least partially positioned over the mouth of the aneurism. The interface side of the patch is configured to form an adherence between the patch and an area of a vessel wall adjacent to the aneurism mouth. The adherence maintains a fixed position of the patch relative to the aneurism mouth.
In one embodiment of the invention the patch includes a vessel interface side and an opposing non-interface side, the patch is configured to have a stowed state when delivered to a mouth of the aneurism. The patch is formed of a thermally active material that moves to a pre-defined shape when electrically heated. The pre-defined shape forms an adherence between the vessel interface side and an area of the vessel wall adjacent to the aneurism mouth. The adherence maintains a fixed position of the patch relative to the aneurism mouth.